Can a shop cut a 35 × 45 down to a smaller size?

Down to a size with the same or a taller proportion, yes, if the head band still fits. Into a square or a wider shape, no — the head band breaks first.

If a form just says "passport size", which one?

In Singapore, 35 × 45 on white — the ICA baseline. That is what the custom-size option here defaults to.

Why are passport photos 35 × 45 mm in some countries and 2 × 2 inches in others?

TL;DR Two standards from two traditions. 35 × 45 mm is the ICAO-derived European size that most of the world adopted; 2 × 2 inches (51 × 51 mm) is the American one, kept by the United States and adopted by India for its overseas processes. A handful of countries use neither — China's 33 × 48, Canada's 50 × 70, Myanmar's 38 × 46, Mexico's 26 × 32 — and those are where guides go wrong most often.

The two families

The 35 × 45 family composes the head at 70–80% of the height and comes with ICAO's guideline sheet. The 2 × 2 family composes the head at roughly 50–69% of a square, leaving more air. A photo made for one family cannot be cropped into the other without either cutting the chin or shrinking the head below the band.

The ones that are neither

China's visa is 33 × 48 with a 58–69% head — the tightest ceiling on this site. Canada's visa is 50 × 70. Myanmar's eVisa is 38 × 46. Mexico's visa is a tiny 26 × 32. New Zealand's passport is a 3:4 digital file, not a print at all. Each of these was recorded wrongly somewhere on the web, several of them on this site until this month, because a guide copied the nearest familiar size.

One from each family, and the exceptions

Document	Size	Head in frame (as we compose it)	Background	Max age	Source
Singapore passport	35 × 45 mm	56–78%	pure featureless white	3 months	www.ica.gov.sg
United States visa	51 × 51 mm	50–69%	plain white or off-white	6 months	travel.state.gov
India passport	51 × 51 mm	50–69%	plain white	3 months	www.blsinternational.com
China visa	33 × 48 mm	58–69%	white or close to white, no edge frame	6 months	bio.visaforchina.cn
Canada visa	35 × 45 mm	69–80%	plain white or light-coloured	6 months	www.canada.ca
Myanmar visa	38 × 46 mm	60–80%	plain white	3 months	evisa.moip.gov.mm
Mexico visa	26 × 32 mm	60–80%	plain white	1 months	embamex.sre.gob.mx
New Zealand passport	51 × 68 mm	65–80%	plain, light-coloured, strongly contrasting with your face	6 months	www.passports.govt.nz

A real case

A heartland photo shop's price list offers "passport size" and "US size". A customer needing a Chinese visa photo took "passport size" — 35 × 45 — and was refused at CVASC for a head over 69%. The shop was not wrong about its sizes; the visa was not on the list.

Common questions

Can a shop cut a 35 × 45 down to a smaller size?: Down to a size with the same or a taller proportion, yes, if the head band still fits. Into a square or a wider shape, no — the head band breaks first.
If a form just says "passport size", which one?: In Singapore, 35 × 45 on white — the ICA baseline. That is what the custom-size option here defaults to.

Sources

Read on the issuing authority's own pages on the dates shown on each document page:

United States visa: travel.state.gov
India passport: www.blsinternational.com (read 2026-09-02)
China visa: bio.visaforchina.cn (read 2026-09-06)
Canada visa: www.canada.ca (read 2026-09-06)

SGfoto is independent — not affiliated with or endorsed by any government or issuing authority — and does not guarantee acceptance. Requirements change; the authority's page is the one that counts. Rebuilt 2026-09-06.